This invention relates to handling systems for mail or other substantially flat articles, and more particular to a take-away mechanism from a singulator for such system, which mechanism is adapted to handle articles of varying thicknesses, sizes and weights, is adapted to control spacing between articles/mail pieces leaving the take-away mechanism, and may provide a doubles resolver function.
Mixed mail received at a post office or other location must be sorted and/or otherwise processed so as to be directable to a desired location. To accomplish this function, random items of incoming mail are typically stacked, either manually or otherwise, for feeding to a first mechanism which singulates the mixed mail so that only a single piece of such mail, which is properly oriented and spaced, is passed on to the sorting or other processing mechanism of a mail handling system. The singulation mechanism may include both a singulation head and a take-away mechanism from such head. The functioning of these two components must be coordinated to resolve doubles, to avoid jams, to avoid damaging the mail, and to assure proper spacing being between successive pieces of mail leaving the take-away mechanism.
While many mechanisms currently on the market do an adequate job of singulating and taking away certain types of mail, increasing demands are being placed on such systems, both as to the range in size, thickness and weight of the mail pieces to be handled and as to the speed at which such systems are to operate, while still maintaining high controllability on the outputted mail, low jam rate, substantially no damage to the mail being handled, and substantial elimination of doubles passing into the sorting or other equipment beyond the take-away mechanism. For example, a specification for mail pieces to be handled in such a high performance system might include pieces ranging in thickness from 0.007xe2x80x3 to 1.25xe2x80x3, pieces ranging in weight from 0.03 oz to 6.0 lbs, and pieces ranging in size from 3.5xe2x80x3xc3x975.0xe2x80x3 or 4xe2x80x3xc3x974xe2x80x3 to 15xe2x80x3xc3x9715xe2x80x3. These variations in thickness, weight and size must be handled without sacrificing throughput, which may be up to approximately 14,500 mail pieces per hour, although this maximum rate may vary somewhat with the size of the pieces being processed, and while still maintaining separation between mail pieces within close tolerances to prevent operational problems on down stream equipment. A system capable of reliably achieving this level of performance without jams and other problems does not currently exist and, in particular, a take-away mechanism from the singulator of such a system for facilitating such performance is not currently available. Similar problems can arise in systems for handling packages on other substantially flat articles of varying size, thickness and weight.
In accordance with the above, this invention provides a take-away mechanism from a singulator of a handling system for substantially flat articles such as mixed mail, the mechanism being particularly adapted for use with articles that are of varying thickness, size and weight. The mechanism includes a drive member extending for a selected length in a direction from which articles exit the singulator; a driver moving the drive member in such direction and away from the singulator at a selected rate; and first and second components spaced from each other along the length of the drive member and mounted to both permit a piece of mail to pass between each component and the drive member and to apply selected pressure to the article against the drive member, the components combining to apply pressure along at least a substantial portion of the length of the drive member. The drive member is at least one belt and includes at least three spaced belts for a preferred embodiment, the driver including at least one roller over which the belts pass, all belts being driven by a common driver. For a preferred embodiment, the belts are timing belts and the drivers include a plurality of rollers, at least one of which is driven, each of which rollers has at least three grooves formed therein, each timing belt fitting in a corresponding groove in each roller. At least one of the components, and preferably both components, include at least two pressure members mounted to substantially apply pressure between the belts of the drive member, but not over the belts. For a preferred embodiment, at least one drive belt is formed of or covered by a material with a high coefficient of friction.
The driver preferably includes a servo motor, detectors for detecting articles at selected locations along the mechanism and controls responsive to the detectors for operating the servo motor to selectively control spacing of articles exiting the mechanism. The servo motor is preferably a start-stop servo motor, the controls stopping and starting the motor, and thus the drive member, to control article spacing. The detectors are at least at an exit end of the mechanism and at a location along the member near the rear-most one of the components.
The drive member is preferably formed so as to minimize slippage between the member and articles pressed thereagainst, the drive member having a surface in contact with articles which is of a material with a high coefficient of friction for preferred embodiments.
The driver preferably moves the drive member at a rate higher than the rate at which the singulator discharges articles to the take-away mechanism, this rate being approximately 15% to 20% faster for preferred embodiments.
For preferred embodiments, at least one of the first and second components is at least one wheel biased against the drive member. Each of the wheels may be mounted at the end of a spring biased arm, which arm is angled at an angle, for example approximately 45xc2x0, in the direction of drive member movement. Each wheel has a surface in contact with the articles, which surface may for some embodiments be of a material having a significant coefficient of friction. Each of the wheels may be substantially free spinning) and each of the wheels are preferably independently biased. For a preferred embodiment, the at least one wheel forms a rear or trailing one of the components.
At least one of the first and second component may also be at least one finger biased against the member/belt, the fingers preferably being independently biased when there are a plurality of fingers. For a preferred embodiment, the at least one finger forms a forward or leading one of the components.
For a preferred embodiment, the articles are pieces of mixed mail and the components are biased to permit mail having variations in thickness between approximately 0.007 inches and 1.25 inches to pass between the drive member and the components. The spacing between the first and second component in the direction of travel is preferably less than the length of the shortest article being taken away by the mechanism.
The foregoing and other objects, features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.